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authorAl Viro <viro@zeniv.linux.org.uk>2018-07-09 16:27:23 -0400
committerAl Viro <viro@zeniv.linux.org.uk>2018-07-12 10:04:30 -0400
commitedc2b1da779887c74ade799574efc5819906598f (patch)
tree5eab5c683da0e821f5591152c80403e4b070f7c1 /fs/namei.c
parent5014c2f378ca3f6ddfe310e4b5ef7027acfc2d45 (diff)
downloadlwn-edc2b1da779887c74ade799574efc5819906598f.tar.gz
lwn-edc2b1da779887c74ade799574efc5819906598f.zip
make path_init() unconditionally paired with terminate_walk()
including the failure exits Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/namei.c')
-rw-r--r--fs/namei.c32
1 files changed, 16 insertions, 16 deletions
diff --git a/fs/namei.c b/fs/namei.c
index 8311dce1c649..1b5c58ad4113 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2125,12 +2125,15 @@ OK:
}
}
+/* must be paired with terminate_walk() */
static const char *path_init(struct nameidata *nd, unsigned flags)
{
const char *s = nd->name->name;
if (!*s)
flags &= ~LOOKUP_RCU;
+ if (flags & LOOKUP_RCU)
+ rcu_read_lock();
nd->last_type = LAST_ROOT; /* if there are only slashes... */
nd->flags = flags | LOOKUP_JUMPED | LOOKUP_PARENT;
@@ -2143,7 +2146,6 @@ static const char *path_init(struct nameidata *nd, unsigned flags)
nd->path = nd->root;
nd->inode = inode;
if (flags & LOOKUP_RCU) {
- rcu_read_lock();
nd->seq = __read_seqcount_begin(&nd->path.dentry->d_seq);
nd->root_seq = nd->seq;
nd->m_seq = read_seqbegin(&mount_lock);
@@ -2159,21 +2161,15 @@ static const char *path_init(struct nameidata *nd, unsigned flags)
nd->m_seq = read_seqbegin(&mount_lock);
if (*s == '/') {
- if (flags & LOOKUP_RCU)
- rcu_read_lock();
set_root(nd);
if (likely(!nd_jump_root(nd)))
return s;
- nd->root.mnt = NULL;
- rcu_read_unlock();
return ERR_PTR(-ECHILD);
} else if (nd->dfd == AT_FDCWD) {
if (flags & LOOKUP_RCU) {
struct fs_struct *fs = current->fs;
unsigned seq;
- rcu_read_lock();
-
do {
seq = read_seqcount_begin(&fs->seq);
nd->path = fs->pwd;
@@ -2195,16 +2191,13 @@ static const char *path_init(struct nameidata *nd, unsigned flags)
dentry = f.file->f_path.dentry;
- if (*s) {
- if (!d_can_lookup(dentry)) {
- fdput(f);
- return ERR_PTR(-ENOTDIR);
- }
+ if (*s && unlikely(!d_can_lookup(dentry))) {
+ fdput(f);
+ return ERR_PTR(-ENOTDIR);
}
nd->path = f.file->f_path;
if (flags & LOOKUP_RCU) {
- rcu_read_lock();
nd->inode = nd->path.dentry->d_inode;
nd->seq = read_seqcount_begin(&nd->path.dentry->d_seq);
} else {
@@ -2272,8 +2265,10 @@ static int path_lookupat(struct nameidata *nd, unsigned flags, struct path *path
const char *s = path_init(nd, flags);
int err;
- if (IS_ERR(s))
+ if (IS_ERR(s)) {
+ terminate_walk(nd);
return PTR_ERR(s);
+ }
if (unlikely(flags & LOOKUP_DOWN)) {
err = handle_lookup_down(nd);
@@ -2337,8 +2332,10 @@ static int path_parentat(struct nameidata *nd, unsigned flags,
{
const char *s = path_init(nd, flags);
int err;
- if (IS_ERR(s))
+ if (IS_ERR(s)) {
+ terminate_walk(nd);
return PTR_ERR(s);
+ }
err = link_path_walk(s, nd);
if (!err)
err = complete_walk(nd);
@@ -2666,8 +2663,10 @@ path_mountpoint(struct nameidata *nd, unsigned flags, struct path *path)
{
const char *s = path_init(nd, flags);
int err;
- if (IS_ERR(s))
+ if (IS_ERR(s)) {
+ terminate_walk(nd);
return PTR_ERR(s);
+ }
while (!(err = link_path_walk(s, nd)) &&
(err = mountpoint_last(nd)) > 0) {
s = trailing_symlink(nd);
@@ -3512,6 +3511,7 @@ static struct file *path_openat(struct nameidata *nd,
s = path_init(nd, flags);
if (IS_ERR(s)) {
+ terminate_walk(nd);
fput(file);
return ERR_CAST(s);
}